1. Field of the Invention
The present invention relates to an ink jet recording apparatus and, more particularly, to an ink jet apparatus in which photo-curable ink is used.
2. Description of the Related Art
Recently, as a method to record an image on a recording medium such as a paper, an ink jet recording method in which ink is jetted on a surface of the recording medium and a gravure printing method in which ink which is stored in a concave portion of a plate is copied to the recording medium have been well known. In these methods, the ink jet recording method makes it possible to form an image at low cost and easily in comparison with the gravure printing method which requires making a plate. As the ink jet recording method, there is a photo-curable ink jet method in which photo-curable ink is used. An ink jet recording apparatus of the ink jet method has a recording head 101 which has a plurality of ink jet openings 100, . . . for jetting ink toward the recording medium downward and an irradiation section 102 for irradiating ink jetted on a surface of the recording medium with light (see, for example, Japanese Application Patent Laid-Open Publication No. 2001-310454).
More particularly, the irradiation section 102 has one irradiation element 103 such as a mercury lamp which can diffuse light to irradiate a wide region with light for curing the whole ink jetted on the surface of the recording medium.
However, when curing the ink on the surface of the recording medium by the above described irradiation section 102, the irradiation element 103 irradiates a portion of the recording medium on which the ink is not jetted with light. Thus, there has a problem that it requires a large amount of power and the irradiation section 102 has a short life.
One irradiation element 103 diffuses light to irradiate a wide region with light, so that the light radiated from the irradiation section 103 becomes a reflected light with low lighting intensity on the surface of the recording medium and diffuses around. Therefore, specially, when using ink such as cationic polymerization ink which is cured by light with low lighting intensity, the ink which adhered to ink jet openings 100 is cured by the above described reflected light with low lighting intensity and obstructs ink jet.